Isniah, Sarah, Humiras Hardi Purba, and Fransisca Debora. “Plan Do Check Action (PDCA) Method: Literature Review and Research Issues ”. Jurnal Sistem dan Manajemen Industri 4, no. 1 (July 31, 2020): 72-81. Accessed February 9, 2023. https://e-jurnal.lppmunsera.org/index.php/JSMI/article/view/2186.